Oct. 6, 2010 -- Some people may be more inclined than others to engage in risky behaviors, such as skydiving and the use of mind-altering drugs like cocaine, because of genetic mutations in the brain's dopamine system, a new study suggests.

Dopamine has been associated with sensation-seeking behavior in previous studies. Jaime Derringer, a PhD student at the University of Minnesota, says she and fellow researchers examined mutations called single nucleotide polymorphisms (SNPs) found in eight genes associated with dopamine. An analysis of the genes of 635 people who were part of a study on addiction was performed.

Derringer says it's too early to start screening people for these mutations and that not enough is known about genes and behavior. But the same methods her team used, she says, could be employed to study links between brain biology and risky behaviors, or between brain biology and depression.

Sensation seeking has been linked in previous research to addictions and behavioral disorders. Though sensation seeking seems to be written in the genes, she says that doesn't mean that all individuals with the mutations will do dangerous things.

"Not everyone who's high on sensation seeking becomes a drug addict," she says. "They may become an Army Ranger or an artist."

She says in the study that sensation seeking is an inheritable personality trait, associated with behavioral disorders that have high social costs.

The study is published in Psychological Science, a journal of the Association for Psychological Science.